Firms here should now apply themselves to making sure the Northern Ireland protocol to the Brexit withdrawal agreement will work instead of hoping it might be amended again, a business leader has said.
In a speech this week, former EU Brexit negotiator Michel Barnier warned that checks on goods travelling from Great Britain to Northern Ireland would be an "indispensable" part of the withdrawal agreement.
However, Prime Minister Boris Johnson has vowed that there will be no checks.
But in a speech at Queen's University, Belfast this week, Mr Barnier said the checks would be required to protect the single market. And he said the agreement and protocol could not be reopened again.
Declan Billington, the chief executive of animal feed firm Thompsons and a board member of the NI Food and Drink Association, said firms in Northern Ireland now needed to accept the realities of working within the protocol.
The UK will leave the EU on Friday, though trading arrangements will not change as a year's transition agreement will then begin.
But Mr Billington said firms here needed to turn their sights to the future arrangements. He said: "We have a short window of time to nail down exactly how our protocol works in respect of goods coming to Northern Ireland, and the related costs and complexities."
Under the protocol, Northern Ireland firms trading with Great Britain are expected to need to complete paperwork. Mr Billington said firms need certainty over what protections they will be afforded for trading into Great Britain so that they are not at a disadvantage.
He said his own firm had spent "a lot of time and expense" on preparing for a no deal Brexit and he was glad that such an outcome had been averted with the withdrawal agreement.
The company had devised "complex customs facilitations structuring and new business entities" to ensure it could continue trading with customers in the Republic, he said.